


Sisters In Magic

by FalconHonour



Series: Sacred Twenty-Eight Fics [6]
Category: Harry Potter - J. K. Rowling
Genre: Alternate Universe - Canon Divergence, Friendship/Love, Gen, Pureblood Culture (Harry Potter), Pureblood Lily Evans Potter, Pureblood Society (Harry Potter), Unbreakable Vow (Harry Potter), accidental adoption
Language: English
Status: Completed
Published: 2020-05-04
Updated: 2020-05-09
Packaged: 2021-03-03 02:40:33
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,693
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24007510
Author URL: https://archiveofourown.org/users/FalconHonour/pseuds/FalconHonour
Summary: The arrival of Petunia's Hogwarts letter causes quite a stir in the Evans household. Desperate to comfort her friend, nine-year-old Narcissa Black promises she will always consider Lily her sister, no matter what. Neither girl is quite prepared for the consequences.
Series: Sacred Twenty-Eight Fics [6]
Series URL: https://archiveofourown.org/series/1572622
Comments: 9
Kudos: 164





	1. I: The Vow

No sooner had Druella and Narcissa landed in the foyer of 11 Phoenix Avenue, the Evans’ London residence, than Lilyanna came flying down the stairs.

“Narcissa! You’re here! Oh, thank Merlin, you’re here!” Barely curtsying to Druella, she grabbed Narcissa by the hand and positively dragged her upstairs. Narcissa would have protested, but there was a desperation in Lilyanna’s manner that stopped her.

Safe behind the wards and thick wooden door of Lilyanna’s sumptuous bedroom, the redhead threw herself into Narcissa’s arms and burst into tears.

“Lilyanna?” Narcissa staggered backwards, just a fraction, under Lilyanna’s weight, tightening her arms around the other girl on instinct, “What’s wrong?”

Her mind was jumping even as she spoke. She hadn’t seen Lilyanna this distressed for years, not since they’d turned seven and started their Occulmency and deportment lessons. It wasn’t proper for a girl of their standing to lose control of their emotions – not to this extent. Whatever had happened this morning must have been truly shocking to upset Lilyanna quite so much.

Whatever Narcissa had been expecting Lilyanna to say, however, it wasn’t the next few words.

"Petunia's letter came today. Her Hogwarts letter. And Mummy just burned it. Threw it in the fire without even opening it. She wrote to Dumbledore, saying that Tuney wouldn't take the place because she had a place at a Muggle school. _A Muggle_ school. _"_

The disdain for such a place was clear in Lilyanna's voice even through her tears, "A Muggle School," she repeated. "As though such a place could ever be worthy of my sister.”

“What? Why would she do that? Petunia’s an Evans, of course she’s going to go to Hogwarts!” Narcissa reeled back in shock, and sensing her flinch, Lilyanna lifted her head to look her in the eye, her green orbs wide.

"But… Narcissa…Surely… Your mother’s Tuney’s godmother. You must know she’s ill!”

“Ill how?”

Narcissa couldn’t stop the question. It wasn't as if she hadn't heard whispers before, but she'd never known what the adults were talking about. Not properly. And while she’d been invited over to 11 Phoenix Avenue or Yewroot Manor to play with Lilyanna numerous times, Petunia had never joined them. There had always been some excuse why she couldn’t. Narcissa had never thought to question it before, but now Lilyanna was suggesting there might be some reasoning behind the older girl’s secluded life. She couldn't help but be curious.

Sadly, Lilyanna scratched her head, idly ruining the elaborate style her mother had had the Elves weave her copper curls into only that morning, "I'm not sure," she finally answered, "I think she's scared of her magic. She doesn't want to use it and it's making her ill."

"But who'd be scared of magic?" Narcissa laughed. Even the words sounded preposterous. How could anyone be _scared_ of the beautiful force that was woven into their everyday lives, into their very blood?

Lilyanna shrugged. "I don't know, but I think Tuney is. She screams herself sick every time someone does a spell around her.”

Unable to help herself, Narcissa gaped like a codfish. In all her nine years of life, she’d never heard of such a thing!

“But that means…” She trailed off as the magnitude of Lilyanna’s words sank in. Lilyanna nodded, “She won't be going to Hogwarts in September. How can she? And that means she won’t be at Hogwarts with us. She won't be able to show me what to do. Where to go. Who to make friends with. What teachers to avoid…"

Lilyanna’s voice trailed off as she broke down again. Narcissa wrapped her arms around her impulsively. "My sisters will do that, Lilyanna. Bella and Meda will show you. They'll treat you like a sister, just like they treat me. So, we'll be fine, you'll see. And Tuney will only go away for a while. Just until she feels better. When she feels better, she'll join us at Hogwarts. You'll see."

Even as she was saying the words, though, Narcissa wasn't sure they were true. Not for the first time, she wished Meda had come with them. Meda was eleven, about to start Hogwarts and she always knew what to say to make someone feel better. Always. But Mama had only agreed to bring Narcissa because she’d begged, pointing out that it was Lily’s owl to her that had alerted them to the fact that they were needed at Phoenix Avenue, not a letter from Lady Evans to Mama. Bella and Meda, their fierce curiosity and Meda’s excitement at her Hogwarts letter notwithstanding, had been dispatched to the tender mercies of Miss Skye and their deportment lessons.

“Will you swear to it?” Lilyanna broke into Narcissa’s musings, her hands clutching at Narcissa’s wrists, “Will you swear to it on Merlin, Morgana and all the Four?”

Her green eyes, still damp with tears, burned into Narcissa’s sapphire ones, utterly compelling in their intensity.

Without quite meaning to, Narcissa nodded, “ _Bien Sur_ ,” she answered, choosing to use the French her parents expected them to speak at home over English, because it seemed to suit the solemnity of the moment better, “You’ve always been like a sister to me, Lilyanna. Let’s make a promise that will always be true.”

“Lily,” the other girl choked, and Narcissa blinked, “Lily?”

“It’s what Tuney and my parents call me. I don’t like Lilyanna. It’s too long. If you’re going to be my sister, you have to call me Lily.”

“Cissy. Or Cissa.” Rather than answer with a confirmation, Narcissa responded by proffering her own nickname, one that protocol demanded only her closest family were allowed to call her.

Lilyanna – Lily - nodded, and drew in a deep breath, “Lilyanna Helena,” she confided, “You’ll have to use my full name for the oath or it won’t be a proper promise. It’s Lilyanna Helena.”

“Narcissa Chastity,” Narcissa echoed.

The formalities settled, the nine-year-olds smiled at each other and sat cross-legged on Lily’s bed, hands clasped in one another’s.

"By the magic of Merlin, of Morgana and all the Four, I, Lilyanna Helena Evans, promise to Narcissa Chastity Black…”

“By the magic of Merlin, of Morgana and all the Four, I, Narcissa Chastity Black, promise to Lilyanna Helena Evans…”

“…that I will always hold her to be my sister, as though she were mine by blood. By this promise…”

“… she is mine and I am hers. May our magic ever run in harmony, from this day until our last.”

“...From this day until our last.”

Their young voices overlapped, matching each other’s beat for beat and word for word, until, on the last phrase, they melded together perfectly.

Eyes squeezed shut to mark how serious their pledge to one another was, neither of them saw the way a pale blue tendril shot out of Lily’s hand and merged with a black one that extended from Narcissa’s, until, utterly interwoven, the braid of magic cleaved itself in two and sank gently back into both girls’ left wrists and into the blood that was being pumped back to their hearts.

Two miles away in Duske Knight Square, Cygnus Black jolted at his desk. Across London, in the prestigious Godric’s Gauntlets duelling club, Robert Evans did the same, though he at least turned his into a subtle feint against his opponent.

Both of them had just felt the exact moment when Lady Magic herself had accepted their daughters’ vow.


	2. II: The Aftermath

Narcissa and her mother had no sooner landed in the family parlour at Duske Knight Square than her father flung the door wide, fixing her with a gimlet stare.

“Narcissa Chastity Black. My study. Now.”

Druella flashed a surprised glance at her youngest. Cygnus didn’t favour Narcissa the way he did Bellatrix – Narcissa had always been far more her daughter than his, in both looks and temperament – but neither was he ever normally this angry with her. He hadn’t called her into his study for three years, not since she’d thrown a tantrum over being sent to bed after helping him welcome the guests for their Beltane ball. He hadn’t needed to, not after Occulmency lessons had reined in Narcissa’s more emotional tendencies.

“You’d better go, Cissy,” she said softly, as Narcissa looked to her, her big blue eyes wide with fear, “It’ll be better to get it over with.”

Narcissa nodded and dropped a deep curtsy to her father, who still stood watching her keenly.

 _“Oui, Papa,”_ she whispered, before turning to Druella, “ _Thank you for taking me with you, Maman. Lily appreciated it very much.”_

Druella started slightly at Narcissa’s casual use of a nickname for the younger Evans daughter, Lilyanna, but before she could question it, Cygnus, impatient as always, had turned on his heel and stalked towards his study, Narcissa trailing in his wake.

* * *

Narcissa lingered over facing her father. Even as his eyes burned into the back of her head, she refused to look at him, concentrating instead on closing his study door utterly perfectly. Eventually, however, it clicked into place, and she had no choice but to turn, oh, so slowly, to look at him.

“Papa?”

“Would you care to explain to me why, as of half past ten this morning, my magic now considers Lady Lilyanna Helena Evans to be my daughter and a member of the House of Black?”

Narcissa gulped. She hadn’t heard her father speaking like this, biting out every word individually, since Bella had taunted Lucius Malfoy into trying to ride his father’s prize unbroken stud Granian and nearly got him killed in the process.

For several seconds, she couldn’t speak, desperately trying to use her Occulmency lessons to help her marshal her thoughts. What in Merlin’s name had she and Lily done and how could she explain it to Papa in a way that he would understand?

“Narcissa. I’m waiting.” Papa growled.

She flushed, “I didn’t mean to!” she cried, the words coming out as rather more of a wail than she would have liked, “I don’t even know what you mean, Papa! I only promised I’d consider Lily a sister!”

“You did what?” Papa froze and looked at her, his grey eyes steely. “Tell me exactly what happened.”

“Petu- Lady Petunia got her Hogwarts letter this morning, just like Meda did, but Lady Evans refused to let her go because using magic upsets her. Lily was upset that Lady Petunia wouldn’t be at Hogwarts with us; wouldn’t be able to help her get used to school. I wanted to make her feel better, so I told her that she needn’t worry, that Bella and Meda would treat her like they treated me. Lily begged me to swear to it, so I did. That’s all, Papa, I promise!”

Suddenly, the words were coming in a torrent, as Narcissa pleaded with her father, desperate to make him see that, whatever she and Lily had done, they hadn’t meant to do any harm.

Papa pressed his hands together under his nose and blew out over the tips of his fingers in a gush.

“Did you promise on Merlin, Morgana and the Four? And did you use each other’s full names?” he said slowly, clearly struggling to control his temper.

Narcissa felt her eyes go wide. What a silly question!

“ _Bien Sur_ , Papa. That’s what you do with all important promises, isn’t it?”

She knew instantly that she’d said the wrong thing. Papa pinched the bridge of his nose and muttered furiously under his breath for a moment.

“That wasn’t a normal promise, you silly girl.The two of you have just sworn a binding magical oath that you hold each other to be sisters. An Unbreakable vow, if you will. Has Miss Skye taught you about those yet?”

Narcissa nodded, a glimmer of just what she and Lily might have done beginning to dawn on her.

“Essentially, in the eyes of Lady Magic, you are now Lady Narcissa Chastity Black-Evans, and Lilyanna is Lady Lilyanna Helena Black-Evans.”

Narcissa swallowed hard. She hadn’t expected that. She'd only wanted to make Lily smile again.

“Papa, I’m…” she began, but her father held up a hand, “I’m tempted to tell you to ignore it, to carry on treating Lady Lilyanna with all the formality you always have before, but I can’t. Especially not when you’re so young. It would damage your magic and we can’t have that. If nothing else, Lord Evans would never forgive me. So, I have spoken to him, and we have decided that while you are allowed to treat each other as sisters in the presence of your immediate families, by which I mean your parents and siblings, the moment there is anyone else around, it is back to formality. Do you understand me?”

Narcissa nodded, her mind whirling. Only treating Lily as her sister in front of Bella, Meda and Mama and Papa and Lord and Lady Evans wouldn’t be difficult now, when they were more or less the full extent of her social circle, bar a few other Pureblood girls she shared dancing lessons with. But then her mind jumped. She was getting her first wand this summer. She’d be off to Hogwarts in two years…

“But Papa, what about Hogwarts? The Sorting…”

She trailed off as Papa pursed his lips, “We’ve two years before we need to cross that bridge. But you mark my words. I will bring all the wrath of the House of Black down on Dumbledore before I let you and Lady Lilyanna be sorted as Black-Evans.”

“Yes, Papa,” Narcissa curtsied, and her father waved her away, “Go. Get out of my sight before I change my mind and decide to punish you after all.”

Narcissa didn’t need telling twice. She curtsied again and fled, always knowing that she’d got away far more lightly than she might have done.

* * *

“What are we going to do, Druella? Narcissa’s not so much of an issue – the Blacks are the senior line, so her magic won’t have been subsumed by the Evans magic as much as Lilyanna’s will have been by hers. With any luck, she’ll be married off before Sirius takes my place as the head of the family, and our wayward heir won’t even notice the difference in the magic. But Lilyanna’s a different story. Even _Sirius_ can’t fail to notice that Lilyanna _Evans_ is considered one of ours when the magic becomes his.”

“Well, you know the answer, don’t you?” Narcissa, on the stairs on her way to bed, heard her mother’s voice through the open parlour door and paused to listen, “You’ll simply have to write to Robert and push for a match between Sirius and Lilyanna, so that she’s already a Black by law before any of this becomes a problem.”

“If Sirius was ours, I would, but Orion’s his father. It’s his right to make a match for his son, even if I have to approve it. I don’t like going over my brother’s head, even if I am the patriarch.”

“Do you have a choice? Robert will understand why you’re breaking with tradition, just this once. And Sirius will do as he’s told, if I have anything to say about it. Walburga might let her sons run wild because she’s too proud of having borne them to care for how she drags them up, but I’ll see to it. Why, I’ll have Sirius thinking it’s _his_ idea to court little Lilyanna before he’s out of Hogwarts, you see if I don’t.”

Narcissa clapped a hand over her mouth to stifle her giggles. She’d known her parents would make everything work out. Lily was going to be her cousin as well as her sister when they grew up! They’d have so much fun, running Duske Knight Square and Grimmauld Place and all the other Black properties scattered around the British Isles together! So much fun!

Turning on her heel, she scampered up the stairs, her lips twitching as she struggled to clear her mind so that her sisters wouldn’t see her secret in her eyes. After all, why should they find out? She was the one who’d sworn to call Lily her sister in the first place, not them!


End file.
